Currently Being ModeratedMay 14, 2013 8:04 PM (in response to aapl.crox)
How do I tell time machine to treat content in this new drive the same as the old one?
You can't. The most that you can do is to copy the Time Machine backup from the old backup drive to the new one. If that's what you want to do, continue as follows.
Although the documentation says you can copy Time Machine backups in the Finder, it's very slow and sometimes doesn't work at all.
Launch Disk Utility, open the built-in help, and search for the term "Duplicate." Follow the instructions. Turn Time Machine in its preference pane while copying the volume.
Currently Being ModeratedMay 14, 2013 8:10 PM (in response to Linc Davis)
Sorry maybe I wasn't being clear. My TM drive is not changing. It's staying the same. But my media drive is getting upgraded. So for example, say I have 500Gb of music. Right now I'm upgrading to a drive of size 2TB. I copy over the 500GB of music to the new drive. Now TM will think this new 500GB of data is new and copy it again to TM. I don't want that since clearly the data is already in TM. How do I tell TM that nothing has changed, I'm only changing drive (please don't keep a duplicate copy of the data in the TM drive and waste space).
Currently Being ModeratedMay 14, 2013 8:24 PM (in response to aapl.crox)
Time Machine will treat each drive independently, and will re-backup files you have moved to a different drive. Your best bet instead of mucking around with the backup and trying to re-link it, is to have TM start over for this drive and create a new backup instance for it.
Currently Being ModeratedMay 14, 2013 8:19 PM (in response to aapl.crox)
That issue is covered on this page: